Carriage brake for typewriters



Deco V N V V O. A. HOKANSON CARRIAGE BRAKE FOR TYPEWRITERS o. A; HOKANSON CARRIAGE BRAKE FOR TYPEWRITERS Dec. 29,1925. 1,567,368 7 O. A. HOKANSON CARRIAGE BRAKE FOR TYPEWRITERS Original Filed April 2, 1923 :s Sheets-Sheet :5

. a I r 23 ,4 l 40 ,37 h 46 J 45 I 3/ 45 4a 5 12 Patented Dec. 29, 1925.

ne qr assess-99K miners As esses TQVWQQDSTOCK TYPE- welraa eneers seamstress LerQla e s ieeaeri r r L r Bees-r B E E fi Application filed April 2,1923, Serial at. 629,272. Rcnewed May 25, 1925.

To all whom it mag concern Be it known that I, Orro A. HOKANSON, a citizen of tl1e U11it-ecl States, residing at lVoodstock, in the county of McI-Ieury and 1 State of Illinois, have invented certain new and useful Improvements in Carriage Brakes for Typewriters, of which the following is a specification.

This invention relates tobraking mechanism for controlling the travel of a typeis simple and'economical to manufacture,

and'which shall be of improved construction.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in -the following specification and it is more particularly pointed out. in the appended claims,

In the drawings Fig. 1 is a rear elevation of a portion of a typewriter, with parts broken away;

Fig. 2 is a top plan view of the. mechanism shown in. Fig. 1;

Fig.3 is a fragmentarysectional view substantially on line .3--3 of Fig. 2;.

Fig. Lis a. vertical section showing the construction .of the brake proper; and

Fig. 5 isa vertical section substantially. on linen-5 of Fig- 4.

Tabulating mechanism. for. typewriters as commonly constructed provides means for releasing the carriage to permitit to travel distances determined by the position .of the tabulator stops. actuated by springimechanism and where relatively long travelis permitted the, carriage gains considerable momentum. before it reaches the end of the travel :so that when the movement is stoppedthe impact may give rise to considerable jar .or shock. In the present inventionrthe braking mechanism for-the carriage is provided in which the braking actionis .proportionalgto the speed so-that excessive speed-and momentum are avoided.

In the drawings, the numeral designates a portion of the framework of the typewriter having an e'scapement wheel 11 journaled thereon controlled by a panof es- The carriage is usually,

capement dogs, oneof which is shown at 12 inthe drawings. The dogs 1:2 are mounted ona plate 13 supported by rocker arms 14 to move back and forth acrossthe plane of the escapement .wheel 11 to produce a step-bystep movement of the carriage during writing operation. Theholding dog 12 is pro vided with alug l5 engaged by a pin 1(} 011 a member 17 pivoted at 18 tothe supporting plate 13. The pivoted member 17 has a cam member 19 which overlies a roller 20 mounted on an arm 21 carried by apivoted barBQ. The bar- 22 pivotally connected at 23th) a lever 2s fulcrumed at 25 on the fran'le 10. A link 26 connects the lever 24 with a tahulator key lever, not shown. The arm 21. carries a spring 27 which supports a. pivoted bar 28 having an abutment linger 29 for engaging tabulator stopsBO on the stop bar 31. W hen the tabulatorkey isdepressed the pivoted member 17 is given a counterclockwise movement, as viewed in Fig. 1, so that the dog 12. is pressed downwardlyout of contact with the teeth of the escapement wheel 11, thus freeing the platen carriage for tabulator movement in the manner familiar to those skilled in the art. At the same time the depression ofthe tabn lator key lifts the abutment 99 into thepath ofthetahnlator stopsBO thatthe carriage is arrested when a stop strikes .the abutment 29. If the operation of the tabulator key. should cause the abutment 29 to engage the lower edge of the stop the spring 27 will be ,co 'npresse d so that as soon as the carriage begins to moyethe abutment .29 will be raised by the expansionofthe spring into thepath of the next stop. A pivoted dog 32is carried by thebar 28. and prevents rcboun d of the carriage. The mechanism thus far described is well known in the art and is that employed on the present Woodstock typewriter.

The frame member 10 carries a support 33 to which a bracket is secured by screws 35. A tongue 36 is out from the bracket 3% and bent outwardly, as shown in Fig. 4, and carries a stud 37 riveted ,or otherwise secured thereto. AshaftfBS has one end journaled in an opening in the stud 37 and has its otherend journaled in a plate 39 attached to the top of the bracket 34; by vscrews 40. A cylindrical casing -l1 is sccured to the bracket at by rivets 1:2 and has an openings?) through which the shaftextends into the casing 41. A circular plate 44 is fixed to the shaft 38 and rotates therewith within the casing 41. The plate 44 carries a pair of pins 45 on which are loosely mounted brake shoes 46 having openings 47 therein to engage the pins 45. A cover 48 retains the brake shoes 46 within the casing and is held in place by the plate 39. It will be apparent that rotation of the shaft 38 in a counterclockwise direction, as viewed in Fig. 5, will move the brake shoes 46 outwardly by centrifugal force until they engage the inner face of the casing 41. Friction between the shoes and easing will tend to turn the shoes outwardly about their pins 45 and thus increase the braking action.

The plates are loosely mounted on the pins 45 and if desired one or more of the pairs of plates may be reversed in their positions so that the plates will trail behind the pins during rotation instead of being pushed ahead of the pins. When a reversal of this kind is made the operation of the plates will be the same as would take place if the shaft 38 were rotated in a clockwise direction, as seen in Fig. 5. l Jith a movement of this kind the braking action would depend upon the centrifugal force and will not be augmented by the friction acting to 1P jam the plate against the casing. It will be apparent that by varying the number of plates arranged to be drawn behind the pins the braking action may be reduced to suit diflerent conditions and'carriages of difierent weights. The same brake may be used for different lengths of carriages by simply arranging the brake plates to give the requisite amount of retarding action.

The shaft 38 is driven by a pinion 49 secured thereto which meshes with a gear 50 secured to a shaft 51 journaled in a bracket 52, the bracket being pivoted on the stud shaft 37. The shaft 51 carries a pinion 53 in the plane of the platen carriage rack bar 54. A pin 55 is mounted on the bracket 52 and engages a slot 56 between the bifurcations of a forked arm 57. The arm 57 is pivotally mounted at 58 on a bracket 59 carried by the lever 24. A screw 60 passes through a slot 61 in the arm 57 and is threaded into the bracket 59 to hold the arm 57 in various positions of adjustment about its pivotal support 58. Movement of the tabulator key lever will raise the arm 57 and swing'the bracket 52 about its pivot 37 to bring the pinion 53 into engagement with the teeth of the rack bar 54. The arm 57 is adjusted about its pivotal support 58 to such a position that the pinion 53 will mesh with the teeth of the bar 54 prior to the release of the escapement wheel so that when the carriage'is freed from control of the escapement mechanism it will have driving connection with the brake shaft 38. It is not necessary that the teeth of the pinion 53 bottom in the spaces between the rack bar teeth, but it is only necessary to secure a driving action between the rack bar teeth and the pinion. It will be apparent that an increase in the speed of the platen carriage will increase the rate of rotation of the shaft 38, thus increasing the centrifugal action on the brake shoes 46 and consequently the resistance of the brake. In practice it has been found that the mechanism secures a practically uniform speed of the carriage brake irrespective of the distance of travel and the braking mechanism can be adjusted by changing the position of the brake shoes 46 to secure the desired speed for any particular machine.

I claim 1. The combination with a platen carriage rack, of an escapement wheel for controlling said rack, a platen carriage brake, means for connecting said brake with said rack independently of said escapement wheel and while said rack is in operative connection with said escapement wheel, a

dog for controlling said escapement wheel,

and means for releasing said escapement wheel from said dog subsequent to connection of said brake with said rack.

2. In combination, a hollow brak drum a friction member arranged within said drum, a rotary member within said drum, and means for connecting said friction member with said rotary member in either one of .two positions to produce difi erent frictional actions when said rotary member is driven, said frictional member comprising a thin plate having similar flat opposite side faces to permit ready reversal thereof.

3. The combination with a brake drum, of a rotary member arranged within said drum, a plurality of flat friction shoes, arranged side by side within said drum, and means for connecting said friction shoes to said rotary member to permit any one of said shoes to be disposed in either one of two positions to produce different resistances when said rotary member is driven.

4. The combination with a brake'drum, of a rotary member arranged within said drum, a friction shoe, and means for pivotally connecting said friction shoe with said rotary member in either one of two positions so that said shoe will be moved outwardly into a brake drum, of

drum and having a pin mounted thereon, and an elongated brake shoe having an opening adjacent one end thereof for engaging said pin, said member being symmetrical relative to a plane normal to the said pin.

6. A carriage brake for typewriters comprising a drum having a rotary shaft therein, a pair of pins connected with said shaft and spaced outwardly therefrom, and counterpart brake shoes having openings therein for engaging said pins, each of said pins being of sufiicient length to receive a plurality of said shoes.

7. A carriage brake for typewriters comprising a drum, a plurality of friction members arranged on a common pivot within said drum, and means operable by a typewriter carriage for rotating said brake shoes, said brake shoes being movable into varying relation with one another and with said drum to produce different degrees of frictional resistance to rotation. v

8. A carriage brake for typewriters comprising a hollow drum, a plurality of pairs of friction plates positioned within said drum, a rotary member within said drum, means for connecting said plates with said member, said plates being movable into different positions to produce different resis tance to rotation of said member, and means for releasably connecting said rotary member with a platen carriage to produce a brak ing action on said carriage.

9. In combination, a typewriter frame member, an escapement wheel journaled on said frame member, a bracket mounted on said frame member and having a brake drum carried thereby, a rotary member within said drum, planetary gearing for driving said rotary member, and means for shifting said planetary gearing about the axis of said rotary member to move said gearing into operative relation with the platen carriage.

10. In a typewriter, a platen carriage rack, an escapement wheel for controlling said rack, a dog for controlling said escapement wheel, tabulator mechanism for releasing said wheel from said dog, a carriage brake drum, centrifugal friction plates within said drum, a shaft for rotating said plates, a bracket arm pivoted to move about the axis of said shaft, gearing carried by said bracket arm for driving said shaft, a tabulator lever, and means for connecting said bracket arm with said tabulator lever to bring said gearing into operative engagement with said rack when said tabulator lever is operated.

11. The combination with a carriage rack bar, of escapement mechanism for controlling said rack bar, tabulator mechanism for releasing said escapement mechanism, a carriage brake gearing for connecting said carriage brake with said rack bar, and a device 'for shifting said gearing into operative relation with said rack bar when said tabulator mechanism is actuated to release said escapement mechanism, said device being adjustable to regulate the time in which said gearing is engaged with said rack relative to the release of said escapement mechanism.

In testimony whereof I have signed my name to this specification on this 30th day of March A. D. 1923.

OTTO A. HOKANSON. 

